ABSTRACT
Objective To investigate the genotype of D class of carbapenemase of carbapenem－resistant Acinetobacter baumannii in traumatology department, so as to guide the rational use of antibiotics as well as prevent the nosocomial infection. Methods A total of 96 strains of Acinetobacter baumannii were collected in traumatology department. Patient history were analyzed and genotype of carbapenemases of OXA－51,OXA－23,ISAba1－oxa－51 and ISAba1－oxa－23 were analyzed by PCR.Results 70.84% (68/96) of Acinetobacter baumannii were isolated from wound tissue. 12 antibacterial agents were tested, 96 strains of Acinetobacter baumannii showed the highest resistance rate (78.13%) to imipenem and the lowest resistance rate (43.75%) to levofloxacin. Among 23 strains of imipenem－sensitive Acinetobacter baumannii, OXA－ 51 gene expression was not detected in 4 strains, however, OXA－23 gene expression were observed in 5 strains. The gene expression rates of OXA－51,OXA－23, ISAba1－oxa－51 and ISAba1－oxa－23 genes were 100%, 95.89%, 79.45% and 71.23% respectively in 73 strains of imipenem－insensitive Acinetobacter baumannii. The rate of gene expression profile of OXA－51+ISAba1－oxa－51+OXA－23+ISAba1－oxa－23 was 65.75% .Conclusion The strains of imipenem－sensitive Acinetobacter baumannii may have the gene expression of OXA－23 of D class of carbapenemase. The main pattern of carbapenemase－producing was OXA－51+ISAba1－oxa－51+OXA－23+ISAba1－oxa－23 in traumatology department,which might be regarded as one of the mechanisms that led to the high resistance of the bacterium of acinetobacter baumannii to carbapenem antibiotics.